VS 2008 - For Each Loop (App Already Open)

I keep getting a notification that the application is already open. I have multiple users in different sessions on the box, and I thought I coded it right, but for some reason it loops still, but only with this one app??

vb.net
Private Sub clinicalLaunchorSwitch()
Dim CurrentSessionID As Integer = Process.GetCurrentProcess.SessionId
Dim hwnd As IntPtr
Dim prc() As Process = Process.GetProcessesByName("open")
[Code] .....

Maybe I just don't understand Exit For yet? I want to do something like:
For each instance of x.exe then t = t + 1
then
exit for t# of times. Is this possible??